Pumping system and pump therefor



Sept. 13, 1966 H. F. LEOPOLD 3,272,129

PUMPING SYSTEM AND PUMP THEREFOR Filed DSC. 18, 1963 2 Sheets-Sheet l Sept 13, 1966 H. F. LEOPOLD PUMPING SYSTEM AND PUMP THEREFOR 2 Sheets-Sheet 2 Filed DGO. 18, 1963 Amg United States Patent O 3,272,129 PUMPING SYSTEM AND PUMP THEREFOR Hugh F. Leopold, Indianapolis, Ind., assignor to Warner Machine Products, Inc., Muncie, Ind., a corporation of Indiana Filed Dec. 18, 1963, Ser. No. 331,446 6 Claims. (Cl. 103-4) This invention relates to a pumping system for a dishwasher or the like and to a pump for use in such a system.

It is an object of the invention to provide a pumping system which will pump lluid into and out of a dishwasher or the like, which will require but a single drive means, and which will provide a direct coupling between said drive means and a pair of pumps. It isa further object of the invention to provide a pump for use in such a system which will pump fluid when its impeller is driven in one direction and which will remain inoperative when its impelleris driven in an opposite direction, which will be of a compact size, and which can be economically manufactured largely from metal or plastic castings.

In accordance with the preferred form of the invention, as it is adapted for use in a dishwasher, there is provided a reversible motor having a drive shaft projecting outwardly from the ends thereof. A pair of opposed pumps are mounted on the motor and each is provided with a single inlet and outlet. The inlet of the rst of said pair of pumps is connected to a sump in the dishwasher, and its outlet is connected to fluid injection means in the dishwasher. The inlet of the second of said pair of pumps is also connected to the dishwasher sump, and its outlet is connected to a drain.

Each of the pumps comprises a housing formed from a pair of opposed shells defining a generally cylindrically shaped chamber provided with a tangential outlet and an axially disposed inlet. A dam extends inwardly from the circumference of the chamber along a chordal segment thereof adjacent the pump outlet. An impeller mounted on one end of the drive shaft is carried within the chamber with its periphery disposed immediately adjacent the inner edge of the dam. Said impeller has a plurality of arcuate blades which curve outwardly from their inner ends toward t-he impeller periphery. The inner ends of said blades are radially spaced from the impeller axis with the spacing between the inner ends of said blades being disposed in axial alignment with the pump inlet.

Upon rotation of the impeller in a direction to cause the outer blade ends to move by the outlet before the dam, said impeller will pump fluid from the inlet through the chamber for discharge through the outlet. Rotation of the impeller in an opposite direction will not cause said impeller to effect any pumping action so that the pump will remain inoperative. The pair of pumps are oppositely oriented wit-h respect to each other so that upon rotation of the motor drive shaft in one direction, said first pump will pump the fluid in the dishwasher from the sump back to said iluid injection means, and the second pump will remain inoperative. Upon reversing the direction lof rotation of the drive shaft, said second pump will pump the iluid from the dishwasher sump to the drain, and the lirst pump will remain inoperative.

Other objects and features of the invention will become apparent from the more detailed description which follows and from the accompanying drawings, in which:

FIG. l is a side elevation of a pump assembly embodying the invention, with portions thereof being broken away;

FIG. 2 is a vertical section taken on the line 2 2 of FIG. l;

FIG. 3 is an enlarged vertical section taken on the line 3-3 of FIG. 2;

3,Z72,l29 Patented Sept. 13, 1966 FIG. 4 is a side elevation of the impeller shown in FIG. 2; and

FIG. 5 is a side elevation of the impeller shown in FIG. 3.

In the operation of a dishwasher, a predetermined amount of water is injected into the dishwasher from an external source and is mixed with the detergent in the dishwasher. The resultant washing solution is collected in a sump 10, recycled through the dishwasher through an injection means 12 in the form of a spray arm or the like, and subsequently discharged from the dishwasher to aV drain. A predetermined amount of the rinse water is also introduced into the washer from the external water source, collected in the sump 10, recycled through the dishwasher by the injection means 12, and discharged through to the drain. The instant invention provides a pump assembly for eifecting such a recycling of the rinse water and cleaning solution and for discharging them to the drain.

As shown in FIG. 1, said pump assembly comprises an electric motor 14 having outwardly projecting drive shaft ends 16 and 18 simultaneously rotatable inthe same direction upon energization of the motor 14. Said motor is connected to conventional means (not shown) for reversing its polarity so that the shaft ends 16 and 18 can be dirven in both clockwise and counterclockwise directions of rotation. A pair of opposed pumps 20 and 21 identical in construction, but having diierent capacities, are mounted on the opposed ends of the motor 14.

The pump 20 is provided with a casing formed from a pair of cast shells 22 and 24. The shell 22 comprises an axially extending annular skirt 25 having fbosses 26 formed thereon and connected to the motor by bolts 27 for mounting the pump 20 thereon. The skirt 25 is integral with a radially inwardly extending annular wall 28 which terminates inwardly of the skirt 25 in a sleeve 29 concentric with said skirt. The shell 24 comprises -an annular skirt 30 -continuous with a radially inwardly projecting annular wall 31 parallel to the wall 28. Inwardly from the skirt 30, the wall 31 is continuous with a frustoconical wall 32 angling radially outwardly from the wall 31 and continuous at its inner edge with a tubular extension 34 forming the pump inlet. A radially projecting flange 36 on the skirt 30 is seated in a shouldered offset 37 formed in the shell 22 at the juncture of the wall 28 and the skirt 25. The ilange 36 is connected to the shell 22 by a plurality of screws 38j for rigidly interconnecting the shells 22 and 24. As `shown in FIG. l, the shells 22 and 24 form a generally circular chamber having an annular portion 40 formed by the opposed walls 28 and 31, and in open communication with a generally frustocylindrical portion 42 formed by the opposed walls 28 and 32.

The outlet for the pump 20 comprises a tubular extension 44 formed on the shell 24 which extends tangentially outwardly from t-he .annular chamber portion 40. A dam 46 is formed on the shell 24 to extend circumferentially inwardly on a chordal segment of the pump chamber adjacent `one side of the outlet 44. As shown, the dam 46 extends across the annular cham-ber portion 40 parallel with the line of ow through the outlet with its inner end terminating at the outer edge of the chamber portion 42.

The impeller is concentrically carried in the casing chamber and includes a head 48 carried in the pump chamber portion 42 and a cylindrical hub `50 carried in the sleeve 29. The drive shaft end 16 extends through the sleeve 29 and is fxedly connected to the hub 50 by a brass cap 52 press-tit over the shaft end 16. As shown, the cap 52 has axially spaced ribs 54 received in annular offsets in the inner wall of the impeller hub 50 for mounting said cap therein. The outer end of the hub is shouldered for the reception of a ceramic seal 56 received around the shaft end 16 and interposed between the hub 50 and a cartridge seal retained within the opening of the sleeve 29 by a spring clip 60. The cartridge seal is formed from a flexible bushing 58 having a channeled cross-section and received -around the s-haft end 16. The bushing 58 carries a spring 61 acting against the legs of the bushing and urging a collar 62 interposed between said bushing and the seal 56 toward said seal.

The impeller head 48 is carried within the frustoconical chamber portion 42 with its outer edge disposed closely adjacent the wall 28. A plurality of arcuate blades 65 project `outwardly from the head along its face remote from the hub 50. Each of the blades 65 is arcuate in form and extends from a point radially spaced from the axis of the impeller to the outer periphery of said impeller. The inner blade face 66 slopes axially outwardly and lies within the arcuate extent of the next adjacent blade. The inner ends of the bl-ade faces 66 define the locus of a circle having a diameter approximating the diameter of the inlet 34, with the space between t-he inner ends of said blades being disposed in axial alignment with said inlet. The blades have a maximum height adjacent the interconnection of the tbl-ade faces 66 and 67, with the height of said blades progressively decreasing along their arcuate extents toward the periphery `of the impeller. This disposes the faces 67 immediately adjacent the wall 32 in parallelism therewith. As shown in FIG. 2, the periphery of the head 48, and thus the outer edges of the blades 65, lie immediately adjacent the inner end of the dam 46 so that upon rotation of the impeller in a counterclockwise direction as viewed in FIG. 2, the blades 65 will move past the outlet 44 before the darn 46 and will pull iuid through t-he inlet 34 for discharge through said outlet. Conversely, upon rotation of the impeller in a clockwise direction as viewed in FIG. 2, the dam 46 will prevent flow through the outlet 44, and the pump 20` will thus remain inoperative.

The pump 21 is identical in construction with the pump 20 and is provided with a casing formed from a pair of cast shells 22' and 24'. An annular skirt 25 extends around the shell 22' and has bosses 26' formed thereon which are connected to the motor 14 by bolts 27'. The skirt 25' is integral with a radially extending annular wall 28' terminating inwardly of the skirt in a sleeve 29'. The shell 24 has an annular skirt 30' continuous with a radially inwardly projecting annular wall 31' parallel to the wall 28'. A frustoconical wall 32' angles radially outwardly from the wall 31' and is continuous at its inner edge with a tubular extension 34' forming the pump inlet. A ange 36' on the skirt 30 is seated in a shouldered offset 37 in the shell 22 and is connected to the shell 22' by screws 38' for rigidly interconnecting the shells 22' 'and 24'. T-he shells 22' and 24' form a circular charnber having an annular portion 40 formed by the opposed walls 28' and 30' and disposed around a generally frustocylindrical portion 42' formed by the opposed walls 28 and 32'.

The outlet for the pump 21' comprises a tubular extension 44' on the shell 24' which extends tangentially outwardly from the -annular chamber portion 40". A dam 46' formed on t-he shell 24' extends circumferentially inwardly across the chamber portion 40' on a chordal segment thereof adjacent one side of the outlet 44'. The dam 46' is disposed in parallelism wit-h the yline of flow through the outlet 44', and its inner end terminates at the outer edge of the chamber portion 42'.

The impeller includes a head 48' carried in the cylinder chamber portion 42 and cylindrical hub 50' carried in the casing sleeve 29'. The drive shaft end 18 extends through the sleeve 29' and is xedly connected to the hub 50' by a brass cap 52' press-lit on the shaft end 18 and connected to the hub 50' by ribs 54' received in annular offsets in the hub. A ceramic seal 56' disposed around the shaft end 18 is interposed between the shouldered 4 outer end of the hub 50' and a cartridge seal retained within the opening of the sleeve 29' by a spring clip 60'. The cartridge seal is formed by a flexible bushing 58' provided with a channeled cross-section and received around the shaft end 18. A spring 61' acts between the legs of the bushing 58' to urge a collar 62' interposed between said bushing and the seal 56 toward said seal.

The impeller head 48', which is carried within the frusto-cylindrical chamber portion 42', has its outer edge disposed closely adjacent the wall 28' and is provided with a plurality of arcuate blades 65' projecting outwardly from the head face adjacent the casing wall 32. Each of the blades 65' is arcuate in form and extends from a point radially spaced from the impeller axis to the outer periphery thereof. The inner blade -faces 66' slope axially outwardly and each lies within the arcuate extent of the next adjacent blade. The inner ends of the blade faces 66 define the locus of a circle having a diameter approximating the diameter of the inlet 34', with the space between said inner blade ends disposed in axial alignment with said inlet. The blades have a maximum height adjacent the interconnection of the blade faces 66' and 67' with the height of said blades progressively decreasing along their arcuate extents to dispose the blade faces 67' immediately adjacent the wall 32' in parallelism therewith. As shown in FIG. 3, the periphery of the head 48', and thus the outer edges of the blades 65' lie immediately adjacent the inner end of the dam 46 so that upon rotation of the impeller in a counterclockwise direction as viewed in FIG. 3, the blades 65' will move past the outlet 44' before the dam 46' to pull fluid through the inlet 34' for discharge through said outlet. Conversely, upon rotation of the impeller in a clockwise direction as viewed in FIG. 3, the dam 46' will prevent flow through the outlet 44', the pump 21 will thus remain inoperative.

The pump 21 has a smaller capacity than the pump 20. Its chambers 40' and 42' have smaller volumetric capacities that the corresponding chamber portions 40 and 42 of the pump 20. The impeller of the pump 21 also has a fewer number of blades than does the impeller in the pump 20.

As shown in FIG. l, the outlet 44' for the pump 21 is connected to a drain line 70, and the outlet 44 for the pump 20 is connected to the fluid injection means 12. Both the inlet 34' for the pump 21 and the inlet 34 for the pump 20 are connected through a T-joint 72 to the sump 10. In this manner, both of the pumps will draw from the same iiuid source, the sump 10, for discharging said fluid through their respective outlets. However, the construction of the pumps and their orientation with respect to each other will permit only one pump at a time to pump the uid from the sump 10 for discharge through its respective outlet.

The operation of the pump assembly may be described as follows: When it is desired to recycle the fluid in the dishwasher, the motor 14 is actuated to cause the drive shaft ends 16 and 18 to drive the impeller in the pump 20 in a counterclockwise direction as Viewed in FIG. 2 thereby driving the impeller in the pump 21 in a clockwise direction as viewed in FIG. 3. Such rotation of the two impellers will cause the impeller in the pump 20 to be operative for pull'mg uid from the sump 10 through the inlet 34 for discharge through the outlet 44 to the injection means 12. Concurrently, since the inlet 34' is in open communication with the sump 10 through the T-joint 72, fluid from said sump will be in open cornmunication with the pump 21, but will not be moved through said pump because of the direction or rotation of the impeller in said pump with respect to the dam 46', thereby preventing any of the fluid from being discharged through the outlet 44' to the drain line 70. However, when it is desired to drain the dishwasher, the polarity of the motor 14 is reversed to cause its shaft end 16 to drive the impeller in the pump 20 in a clockwise direction as viewed in FIG. 2 and its shaft end 1 8 to drive the impeller in the pump 21 in a counterclockwise direction as viewed in FIG. 3. Such rotation causes the impeller in pump 21 to draw the fluidfrom the sump through the inlet 34 for discharge out the outlet 44 to the drain line 70. Concurrently, the impeller in the pump rotating in a clockwise direction as viewed in FIG. 2 will be inoperative so that it will not pump any uid from the sump 10 back through the outlet 44 to the injection means 12. There may be a tendency, due to pressure differentials for the pump 21 to pull uid from the s-ump even though its impeller is rotating in a counterclockwise direction as viewed in FIG. 3. However, any such pumping action will be negligible, and due to the difference in capacity between the pumps 20 and 21, there will be no fluid discharged through the outlet 44 on the pump 21.

While the pump `assembly has been described as being used in a dishwasher, it is to be understood, of course, that said pump assembly can be used with other devices which require both a recycling and a draining of fluid.

I claim:

1. In a pumping system for a dishwasher or the like, a reversible motor having a pair of drive shaft ends simultaneously rotatable in the same direction, first and second pumps each having a casing providing a generally circular chamber having an axially oriented inlet and a tangentially oriented outlet, a dam extending inwardly from the circumference of said chamber adjacent said outlet, an impeller connected to one of said drive shaft ends and concentrically disposed within said chamber with its periphery immediately adjacent the inner edge of the dam, said impeller having a plurality of arcuate Vblades having their inner ends radially spaced from the impeller axis for pumping Huid through said chamber only during rotation of the impeller ina direction to move the outer blade ends past the outlet before said darn, the inlets on said pumps being connected to sump means on said dishwasher or the like and the outlet on said iirst pump being connected to fluid injection means in said dishwasher or the like and the outlet on said second pump being connected to a drain, said pumps being oppositely oriented with respect to each other whereby upon rotation of the drive shaft ends in one direction said first pump will pump uid from said sump means to said injection means and said second pump will be inoperative and upon rotation of said drive shaft ends in an opposite direction said second pump will pump fluid from said sump rneans to said drain and said first pump will remain inoperative.

2. The invention as set forth in claim 1 in which said first pump has a greater capacity than said second pump.

3. The invention as set forth in claim 1 in which the chamber in each of said pumps has an annular portion in open communication with said outlet and disposed around and in open communication with a generally frusto cylindrical portion in open communication with said inlet.

4. The invention as set forth in claim 1 in which said drive shafts project outwardly from the opposed ends of said motor and the casings of said pumps are mounted on said opposed motor ends.

5. A fluid pump, comprising a casing having a chamber provided with an annular portion extending around and in open communication with a generally frustoconical portion, said casing having an outlet tangentially oriented with respect to said frustoconical portion, a dam fxedly mounted in said casing and extending across a segment of said annular portion adjacent said outlet, and an impeller carried within said frustoconical portion with its periphery immediately adjacent the inner edge of Said dam, said impeller having a plurality of arcuate blades projecting axially outwardly on said impeller and having heights progressively decreasing from their inner ends to the periphery of the impeller, the inner ends of said .blades being radially spaced from the impeller axis and separated from each other and their outer ends terminating at the impeller periphery whereby said impeller will only pump fluid into said chamber and discharge it through said ontlet when it is rotated in a direction to cause the outer. ends of said blades to move past the outlet before said darn, the inner end face of each of said blades lying in the plane of the blade curvature and angled axially outwardly from the said impeller with the innermost edges of said end faces defining the locus of a circle having a diameter approximating the diameter of said inlet.

6. A fluid pump as set forth in claim 5 in which the inner end of each of said blades lies within the extent of the arcuate length of the next adjacent blade.

References Cited by the Examiner UNITED STATES PATENTS 2,030,381 2/1936 Lowe 103-103 2,166,436 7/1939 Harlow 103-115 2,294,135 8/1942 Smith 103-115 2,643,614 6/ 1953 Rosenkrans 103-4 2,784,672 3/1957 Wallace 103-103 2,916,997 12/1959 Terrie 103--2 2,981,464 4/1961 Omohundro 230-123 2,989,925 6/1961 'Brehm et al 103-103 3,099,992 8/1963 La Flame 103-3 3,120,340 2/1964 Strumpell 230-128 MARK NEWMAN, Primary Examiner.

W. I. KRAUSS, Assistant Examiner. 

1. IN A PUMPING SYSTEM FOR A DISHWASHER OR THE LIKE, A REVERSIBLE MOTOR HAVING A PAIR OF DRIVE SHAFT ENDS SIMULTANEOUSLY ROTATABLE IN THE SAME DIRECTION, FIRST AND SECOND PUMPS EACH HAVING A CASING PROVIDING A GENERALLY CIRCULAR CHAMBER HAVING AN AXIALLY ORIENTED INLET AND A TANGENTIALLY ORIENTED OUTLET, A DAM EXTENDING INWARDLY FROM THE CIRCUMFERENCE OF SAID CHAMBER ADJACENT SAID OUTLET, AN IMPELLER CONNECTED TO ONE OF SAID DRIVE SHAFT ENDS AND CONCENTRICALLY DISPOSED WITHIN SAID CHAMBER WITH ITS PERIPHERY IMMEDIATELY ADJACENT THE INNER EDGE OF THE DAM, SAID IMPELLER HAVING A PLURALITY OF ARCUATE BLADES HAVING THEIR INNER ENDS RADIALLY SPACED FROM THE IMPELLER AXIS FOR PUMPING FLUID THROUGH SAID CHAMBER ONLY DURING ROTATION OF THE IMPELLER IN A DIRECTION TO MOVE THE OUTER BLADE ENDS PAST THE OUTLET BEFORE SAID DAM, THE INLETS ON SAID PUMPS BEING CONNECTED TO SUMP MEANS ON SAID DISHWASHER OR THE LIKE AND THE OUTLWT ON SAID FIRST PUMP BEING CONNECTED TO FLUID INJECTION MEANS IN SAID DISHWASHER OR THE LIKE AND THE OUTLET ON SAID SECOND PUMP BEING CONNECTED TO A DRAIN, SAID PUMPS BEING OPPOSITELY ORIENTED WITH RESPECT TO EACH OTHER WHEREBY UPON ROTATION OF THE DRIVE SHAFT ENDS ON ONE DIRECTION SAID FIRST PUMP WILL PUMP FLUID FROM SAID SUMP MEANS TO SAID INJECTION NEANS AND SAID SECOND PUMP WILL BE INOPERATIVE AND UPON ROTATION OF SAID DRIVE SHAFT ENDS IN AN OPPOSITE DIRECTION SAID SECOND PUMP WILL PUMP FLUID FROM SAID SUMP MEANS TO SAID DRAIN AND SAID FIRST PUMP WILL REMAIN INOPERATIVE. 